Public Vulnerability Reports

Oracle Database Server dbms_system.ksdwrt Buffer Overflow Vulnerability



Oracle Database Server is a family of database products that range from
personal databases to enterprise solutions. Further information is
available at:


Remote exploitation of a buffer overflow vulnerability in Oracle Corp.'s
Oracle Database Server could allow attackers to crash the server and
potentially execute arbitrary code.

The problem specifically exists within dbms_system.ksdwrt(), a function
that allows writing messages to alert.log. If a long string is passed as
the second argument to this function, a buffer overflow occurs.


Successful exploitation allows authorized remote users to cause the
Oracle server process to crash and potentially execute arbitrary code.
Authorized users include any users who are members of the SYS or SYSTEM
roles, as well as users who are granted execute permissions on the
dbms_system package.

Successful exploitation of this vulnerability on Microsoft Corp.'s
Windows platforms can lead to a full system compromise, as most systems
are configured to run the Oracle service under Local System. Successful
exploitation of this vulnerability on Linux/Unix platforms usually
compromises only the database because the Oracle service runs under a
non-privileged account.

In cases where Oracle Internet Directory has been installed, an added
exploitation vector exists. This is because Oracle Internet Directory
creates a database user called ODSCOMMON that has a default password of
ODSCOMMON which cannot be changed, thereby allowing any attacker to
connect to the database server and exploit this vulnerability.


The following versions of Oracle Database Server are affected:

    Oracle 9i Database Server Release 2, versions and
    Oracle 9i Database Server Release 1, versions and
    Oracle 8i Database Server Release 1, version

Oracle 10g Database Server is not affected.


iDEFENSE is currently unaware of any workarounds that fully address this


"[This] issue [has] been addressed in Alert 68."


The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2004-0638 to this issue. This is a candidate for inclusion in
the CVE list (, which standardizes names for
security problems.


05/06/2004    Initial vendor notification
05/06/2004    iDEFENSE clients notified
05/06/2004    Initial vendor response
09/02/2004    Public disclosure


Alexander Kornbrust ( is credited with
this discovery.

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Copyright © 2004 Verisign, Inc.

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